Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 4, Issue 7, Pages 3685-3691Publisher
AMER CHEMICAL SOC
DOI: 10.1021/am3007802
Keywords
superhydrophobicity; metallic surface; dual-scale roughness; microcraters; wire electrical discharge machining
Funding
- National Research Foundation of Korea (NRF) [2011-0017530, 2011-001572]
- WCU (World Class University) [R31-2008-000-10083-0]
- Basic Science Research Program [2010-0027955]
- Korea Research Foundation [KRF-J03003]
- Global Frontier R&D Program on Center for Multiscale Energy System
Ask authors/readers for more resources
We present a direct one-step method to fabricate dual-scale superhydrophobic metallic surfaces using wire electrical discharge machining (WEDM). A dual-scale structure was spontaneously formed by the nature of exfoliation characteristic of Al 7075 alloy surface during WEDM process. A primary microscale sinusoidal pattern was formed via a programmed WEDM process, with the wavelength in the range of 200 to 500 mu m. Notably, a secondary roughness in the form of microcraters (average roughness, Ra: 4.16 to 0.41 mu m) was generated during the exfoliation process without additional chemical treatment. The low surface energy of Al 7075 alloy. (gamma = 30.65 mJ/m(2)), together with the presence of dual-scale structures appears to contribute to the observed superhydrophobicity with a static contact angle of 156 degrees and a hysteresis less than 3 degrees. To explain the wetting characteristics on dual scale structures, we used a simple theoretical model. It was found that Cassie state is likely to present on the secondary roughness in all fabricated surfaces. On the other hand, either Wenzel or Cassie state can present on the primary roughness depending on the characteristic length of sinusoidal pattern. In an optimal condition of the serial cutting steps with applied powers of similar to 30 and similar to 8 kW, respectively, a stable, superhydrophobic metallic surface was created with a sinusoidal pattern of 500 mu m wavelength.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available